Source code for adcorr.corrections.solid_angle

from typing import Tuple, cast

from numpy import cos, dtype, floating, number, power

from ..utils.geometry import scattering_angles
from ..utils.typing import FrameHeight, Frames, FrameWidth, NumFrames




def correct_solid_angle(
    frames: Frames[NumFrames, FrameWidth, FrameHeight, dtype[number]],
    beam_center: Tuple[float, float],
    pixel_sizes: Tuple[float, float],
    distance: float,
) -> Frames[NumFrames, FrameWidth, FrameHeight, dtype[floating]]:
    """Corrects for the solid angle by scaling by the inverse of subtended area.

    Corrects for the solid angle by scaling by the inverse of area subtended by each
    pixel, as detailed in section 3.4.6 of 'Everything SAXS: small-angle scattering
    pattern collection and correction' [https://doi.org/10.1088/0953-8984/25/38/383201].

    Args:
        frames: A stack of frames to be corrected.
        beam_center: The center position of the beam in pixels.
        pixel_sizes: The real space size of a detector pixel.
        distance: The distance between the detector and the sample head.

    Returns:
        The corrected stack of frames.
    """
    correction = power(
        cos(
            scattering_angles(
                cast(Tuple[int, int], frames.shape[-2:]),
                beam_center,
                pixel_sizes,
                distance,
            )
        ),
        3,
    )
    return frames / correction